Finding the Fourth Proportional to 131.78, 181.83 and 76.49

Step by Step Solution

1. Step 1: Write the proportion equation
   131.78 : 181.83 = 76.49 : x
2. Step 2: Convert to fraction form
   131.78/181.83 = 76.49/x
3. Step 3: Cross multiply
   131.78x = 181.83 × 76.49
4. Step 4: Simplify right side
   131.78x = 13,907.54
5. Step 5: Solve for x
   x = 13,907.54/131.78
6. Step 6: Final answer
   x = 105.53